Of course, the devil is in the "up to", since no powerline product - or wireless, for that matter - has yet delivered real-world speeds that come close to the theoretical maxima used to market them.

Adaptors based on the 200Mb/s HomePlug AV standard, for example, are so unlikely to go beyond 100Mb/s that no supplier actually equips them with a better Ethernet connector than 10/100.

Belkin, for one, offers a "Gigabit" networking powerline adaptor - reviewed here - and while it exceeds 100Mb/s, it delivers speeds a long way off 1000Mb/s.

The Belkin adaptor uses proprietary technology from chip maker Gigle, so it will be interesting to see how the Netgear kit, based on a spec defined by many different companies, fares. Even with a 500Mb/s cap, it could out-perform the Belkin adaptor - and will certain fly in comparison to 802.11n Wi-Fi.

IEEE P1901 is just one next-gen powerline standard. The other is G.hn, backed by the International Telecom Union (ITU). P1901 was originally set to be compatible with G.hn, but that plan was rejected late last year. It will form the basis for the next version of HomePlug.

G.hn kit is expected later this year.

Netgear's adaptors - some with pass-through power sockets - will be out later this autumn, priced from $159 (£103) per pair. ®